Poly(vinyl chloride) compositions

ABSTRACT

A composition comprising an intimate admixture of (a) 50 to 98 parts by weight of a vinyl chloride polymer having an inherent viscosity of at least 0.4 and (b) 50 to 2 parts by weight of a random addition tetrapolymer containing the following monomers combined in the polymer structure in the following weight percentages: -Weight Percent -Acrylonitrile 15-35  -Methyl methacrylate 5-45 -Indene 5-45 - alpha -methylstyrene or 5-45 -styrene or a -mixture of both - where (a) plus (b) total 100 parts by weight, and the total parts by weight of combined indene plus  alpha -methyl styrene plus styrene in the tetrapolymer (b) is 38-70 parts by weight.

This invention relates to poly(vinyl chloride) plastic moldingcompositions having improved working and performance characteristics,including a higher melt index and a higher heat distortion temperature(HDT).

Poly(vinyl chloride) resins are well known to be useful to mold many endproducts such as bottles, film, sheet, pipe, structural moldings.However, the normal poly(vinyl chloride) resin compositions used to makerigid end products have too low a heat distortion temperature for use inapplications under heat and load because the shape of the product willbecome distorted when approaching the heat distortion temperature. Forinstance, it would be desirable to have poly(vinyl chloride)compositions in the form of pipe and bottles that will stand a highertemperature in service than the standard poly(vinyl chloride) resinshaving a normal 65° to 70° or 71° C. heat distortion temperature. Itwould, moreover, be desirable to have poly(vinyl chloride) moldingcompositions having a higher melt index than the standard commercialresins in order to improve their processability in shaping and formingoperations.

It is an object of the present invention to provide rigid poly(vinylchloride) compositions having improved properties, including a higherheat distortion temperature and a higher melt index, as well as good orimproved flexural modulus and tensile strength, among other mechanicalproperties.

Other objects, as well as aspects, features and advantages of thepresent invention, will become apparent from a study of specification,including the examples and the claims.

The objects numerated above, and other objects, are realized accordingto the present invention by providing a composition or blend of a vinylchloride polymer and certain random tetrapolymers containing indene asone of the monomers.

The vinyl chloride resin of the blend of the invention can be ahomopolymer of vinyl chloride or a copolymer of vinyl chloride with aminor portion of one or more monomers copolymerizable with vinylchloride. In such copolymers vinyl chloride comprises on a weight basisat least about 80 (preferably at least 90) percent of the copolymer andthe copolymerizable monomer comprises up to about 20 (preferably up toabout 10) percent. A wide variety of copolymerizable monomers may beused to prepare such vinyl chloride copolymers. These include vinylidenechloride; vinyl acetate and vinyl stearate; acrylic and methacrylic acidesters; olefins such as ethylene, propylene, isobutylene and the like;vinyl alkyl ethers such as vinyl isobutyl ether, vinyl lauryl ether, andvinyl cetyl ether; acrylic acid and methacrylic acid; acrylonitrile andmethacrylonitrile; diethyl fumarate; maleic anhydride; dimethylitaconate; styrene, N-vinyl carbazole; N-vinyl pyrrolidone; or mixturesthereof.

Methods for the preparation of vinyl chloride polymers are well known inthe art and reported in the literature. See for example Kirk-Othmer,Encyclopedia of Chemical Technology, Third Edition, IntersciencePublishers, Volume 23, pages 886-936, (Copyright 1983), the disclosuresof which is incorporated herein by reference. Vinyl chloride polymersare available from a number of commercial suppliers. For preparingblends of this invention for use in injection molding operations, thevinyl chloride polymer usually has an inherent viscosity (as measured ata concentration of 0.5 gram per 100 grams of cyclohexanone at 25° C.) inthe range of about 0.40 to about 0.70 and more usually in the range ofabout 0.50 to 0.70. Blends of such injection molding grade poly(vinylchloride) homopolymer with our tetrapolymers are particularly useful.Blends of the tetrapolymers with extrusion grade vinyl chloride polymersare also very useful, and the extrusion grade vinyl chloride polymersused in such blends generally have viscosities in the inherent viscosityrange from over 0.70 to 1.2, measured on the same basis. The presentblends usually use a vinyl chloride polymer having an inherent viscosityof 0.54 to 1.

The random tetrapolymers used in the blends of the present invention arepolymers that are the result of addition polymerization of the monomersacrylonitrile, methyl methacrylate, α-methylstyrene and/or styrene, andindene. These random tetrapolymers usually have a relatively lowinherent viscosity. As will be seen, this low viscosity is itself anadvantage.

As used herein inherent viscosity is in deciliters per gram of polymercomposition.

According to the present invention there is provided a compositioncomprising an intimate admixture of

(a) 50 to 98 parts by weight of a vinyl chloride polymer having aninherent viscosity of at least 0.4 and

(b) 50 to 2 parts by weight of a random addition tetrapolymer containingthe following monomers combined in the polymer structure in thefollowing weight percentages:

    ______________________________________                   Weight Percent    ______________________________________    Acrylonitrile    15-35    Methyl methacrylate                     5-45    Indene           5-45    α-methylstyrene or                     5-45    styrene or a    mixture of both    ______________________________________

where (a) plus (b) total 100 parts by weight, and the total parts byweight of combined indene plus α-methyl styrene plus styrene in thetetrapolymer (b) is 38-70 parts by weight, usually 45-60 parts.

The compositions of this invention can include other ingredients, suchas impact modifiers, thermal stabilizers, processing aids, fillers,lubricants, pigments, flame retardants, reinforcing fibers, smokeretardants, antioxidants, and the like.

The compositions of this invention can also contain fillers Examples arecalcium carbonate, wollastonite, silicates such as talc, acicularcalcium silicate, titanium dioxide, potassium titanate, and glassflakes. Amounts of such fillers of up to about 50 parts per 100 parts ofthe combined vinyl chloride polymer plus the random tetrapolymer.

In the foregoing compositions of the invention the more usualcomposition ranges for the tetrapolymer component are

    ______________________________________                    Weight                    Percent    ______________________________________    Acrylonitrile     20-30    Methyl methacrylate                      15-30    Indene            10-30    α-methylstyrene                      15-40    plus styrene    ______________________________________

It is an advantage of our tetrapolymers that they are low molecularweight polymers. This automatically results from the influence of themonomer, indene, on the course of the polymerization; thus indene seemsto act as an automatic chain transfer agent. As a result, the polymersused in making the blends of the invention have an inherent viscosity of0.08 to 0.4, usually 0.01 to 0.36 deciliters per gram. Because of thischaracteristic of the tetrapolymers, their blends with vinyl chloridepolymers result in a polymer blend having not only a higher HDT than thevinyl chloride polymer, but also a much higher melt index. The blends ofthe invention thus not only greatly increase the HDT but also are muchmore easily mechanically worked because of the high melt index.

In the tetrapolymer compositions forming the additive component of ourinvention, we have found that the indene and the α-methylstyrene and/orthe styrene are the main components increasing the HDT, while the polarcompounds, acrylonitrile and methylacrylate contribute to compatibilitywith the vinyl chloride polymer, thus helping to maintain other physicalmechanical properties. One reason that acrylonitrile alone cannot beused to supply the needed polarity is that too much acrylonitrile alsomakes the tetrapolymer less compatible with the vinyl chloride polymer.The reason that indene alone cannot be used as the HDT modifiercomponent is that when the indene content of the additive polymerbecomes too high, the polymer tends to become much less compatible withthe vinyl chloride polymer, and the use of some α-methylstyrenealleviates this problem, although the reason is not well understood.

Properties reported in this application were determined by theprocedures of the following ASTM designations:

Heat Distortion Temperature: ASTM D 648 (264 psi, unannealed)

Tensile Strength: ASTM D 638(Modified)

Flexural Strength: ASTM D 790

Flexural Modulus: ASTM D 790

Melt Index: ASTM D 1238

Also, when inherent viscosity was determined for the tetrapolymers, itwas for a solution of 0.2 grams of the polymer in 100 cc ofdimethylformamide and was measured at 25° C.

The following examples of the compositions of the invention are merelyillustrative and are not to be considered limiting.

In the examples unless otherwise stated, the PVC used in the blends wasan injection grade PVC having an inherent viscosity of 0.68deciliters/gm. for a 0.5 weight percent solution in cyclohexanone, andwhen stabilized with 3 parts by weight of Thermolite 813 per 100 partsof PVC, the PVC had a tensile strength of 8,500 psi, and HDT of 70° C.*,a flexural strength of 12,400 psi, a flexural modulus of 430,000 psi, anotched Izod of 0.26 ft-lbs/sq. in., and a melt index of 0.6 grams/10minutes.

In the examples, Thermolite 813 is di-n-octyltin maleate polymer sold byM & T Chemicals Inc. having the formula

    ((C.sub.8 H.sub.17).sub.2 SnCH.sub.2 O.sub.4).sub.n

having a melting point of 90° C. and specific gravity of 0.6. It is acommonly used thermal stabilizer.

EXAMPLE A

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    15         Methyl Methacrylate    15         α-Methylstyrene    50         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of Acrylonitrile, 5parts of methyl methacrylate, 4 parts of α-methylstyrene, and 47.5 partsof indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 10 parts of methyl methacrylate,10 parts of α-methylstyrene and 2.5 parts of indene was addedcontinually into the reactor over a period of 12 hours through a syringepump. The resulting mixture was further allowed to react for 6 morehours. After completion of the reaction, the polymer obtained wasdissolved into acetone, and reciprocated in excess methanol. The polymerwas filtered, and dried in a vacuum oven for 24 hours at 60° C. Apowdery tetrapolymer was obtained in a 40% yield. The composition of thepolymer was 15 acrylonitrile, 19 methyl methacrylate, 41 α-methylstyreneand 25 indene as determined by C¹³ NMR. The inherent viscosity was0.132.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with a mixing brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties.

The HDT was 81° C., the melt index was 5.5 g./10 min, the tensilestrength was 9,200 psi, the flexural strength was 7,400 psi and theflexural modulus 440,000 psi.

The melt index of a blend made with 65 parts of PVC and 35 parts of thetetrapolymer was 10.6 g./10 min. and the HDT was 82.5° C.

EXAMPLE B

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    25         Acrylonitrile    10         Methyl Methacrylate    20         α-Methylstyrene    45         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 25 parts of Acrylonitrile, 5parts of methyl methacrylate, 10 parts of α-methylstyrene, and 45 partsof indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 5 parts of methyl methacrylateand 10 parts of α-methylstyrene was added continually into the reactorover a period of 12 hours through a syringe pump. The resulting mixturewas further allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered, and driedin a vacuum oven for 24 hours at 60° C. A powdery tetrapolymer wasobtained in a 30.6% yield. The composition of the polymer was 26acrylonitrile, 14 methyl methacrylate, 38 α-methylstyrene and 21 indeneas determined by C¹³ NMR. The inherent viscosity was 0.186.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with mixing a brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties.

The HDT was 79° C., the melt index was 4.2 g./10 min, the tensilestrength was 9,600 psi, the flexural strength was 10,900 psi and theflexural modulus 500,000 psi.

EXAMPLE C

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    30         Acrylonitrile    15         Methyl Methacrylate    15         α-Methylstyrene    40         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 30 parts of Acrylonitrile, and40 parts of indene were charged into a reactor provided with a stirrer.The reactor was purged with nitrogen, and was kept under nitrogenpressure. The temperature of the reactor was held for 5 minutes at 65°C. with stirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 15 parts of methyl methacrylateand 15 parts of α-methylstyrene was added continually into the reactorover a period of 12 hours through a syringe pump. The resulting mixturewas further allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered, and driedin a vacuum oven for 24 hours at 60° C. A powdery tetrapolymer wasobtained in a 49% yield. The composition of the polymer was 26acrylonitrile, 15 methyl methacrylate, 21 α-methylstyrene and 38 indeneas determined by C¹³ NMR. The inherent viscosity was 0.213.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with a mixing brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties.

The HDT was 78° C., the melt index was 2.5 g./10 min, the tensilestrength was 9,700 psi, the flexural strength was 12,000 psi and theflexural modulus 470,000 psi.

EXAMPLE D

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    30         Acrylonitrile    10         Methyl Methacrylate    30         α-Methylstyrene    30         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendistilled in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 30 parts of Acrylonitrile and 30parts of indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 10 parts of methyl methacrylateand 30 parts of α-methylstyrene was added continually into the reactorover a period of 12 hours through a syringe pump. The resulting mixturewas further allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered, and driedin a vacuum oven for 24 hours at 60° C. A powdery tetrapolymer wasobtained in a 54% yield. The composition of the polymer was 24acrylonitrile, 6 methyl methacrylate, 42 α-methylstyrene and 28 indeneas determined by C¹³ NMR. The inherent viscosity was 0.215.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with a mixing brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties.

The HDT was 75° C., the melt index was 3.1 g./10 min, the tensilestrength was 9,100 psi, the flexural strength was 10,500 psi and theflexural modulus 430,000 psi.

When a composition was made with 35 percent of the tetrapolymer the HDTwas 77° C., the melt index was 4.7 g./10 min., the tensile strength was7000 psi, the flexural strength was 9,300 psi and the flexural moduluswas 450,000 psi.

EXAMPLE E

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent    30         Acrylonitrile    15         Methyl Methacrylate    15         α-Methylstyrene    40         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 30 parts of Acrylonitrile and 40parts of indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 15 parts of methyl methacrylateand 15 parts of α-methylstyrene was added continually into the reactorover a period of 12 hours through a syringe pump. The resulting mixturewas further allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered, and driedin a vacuum oven for 24 hours at 60° C. A powdery tetrapolymer wasobtained in a 51% yield. The composition of the polymer in weightpercent was 25 acrylonitrile, 16 methyl methacrylate, 28 α-methylstyreneand 31 indene as determined by C¹³ NMR. The inherent viscosity was0.210.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with a mixing brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties, as noted below:

Results:

The HDT was 74° C., the melt index was 2.7, the tensile strength was8,800 psi, the flexural strength was 11,100 psi and the flexural modulus470,000 psi.

When a composition was made with 35 percent of the tetrapolymer the HDTwas 79° C., the melt index was 4.0 g./10 min., the tensile strength was8400 psi, the flexural strength was 8,300 psi and the flexural moduluswas 490,000 psi.

EXAMPLE F

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    25         Acrylonitrile    20         Methyl Methacrylate    10         α-Methylstyrene    45         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 25 parts of Acrylonitrile and 40parts of indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 70° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of methyl methacrylate,10 parts of α-methylstyrene and 5 parts of indene was added continuallyinto the reactor over a period of 12 hours through a syringe pump. Theresulting mixture was further allowed to react for 6 more hours. Aftercompletion of the reaction, the polymer obtained was dissolved intoacetone, and reprecipitated in excess methanol. The polymer wasfiltered, and dried in a vacuum oven for 24 hours at 60° C. A powderytetrapolymer was obtained in a 40% yield. The composition of the polymerin weight percent was 22 acrylonitrile, 23 methyl methacrylate, 20α-methylstyrene and 36 indene as determined by C¹³ NMR. The inherentviscosity was 0.166.

35 parts by weight of the tetrapolymer was mixed with 65 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with a mixing brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties, as noted below:

The HDT was 82° C., the melt index was 6.7, the tensile strength was7,700 psi, the flexural strength was 5,300 psi and the flexural modulus450,000 psi.

EXAMPLE G

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM              Components    ______________________________________    200              H.sub.2 O    2.5              Sodium lauryl sulfate    1.0              Na.sub.2 S.sub.2 O.sub.8    1.0              Na.sub.3 PO.sub.4 . 12H.sub.2 O    25               Acrylonitrile    20               Methyl Methacrylate    30               α-Methylstyrene    25               Indene    ______________________________________

200 parts by weight of distilled water, 2.5 parts of Sodium laurylsulfate, 1.0 part of Na₃ PO₄.12H₂ O, 18 parts of acrylonitrile, 12 partsof methyl methacrylate, 8 parts of α-methylstyrene, 25 parts of indeneand 0.7 parts of Na₂ S₂ O₈ were charged into a reactor provided with astirrer. The reactor was purged with nitrogen, and was kept undernitrogen pressure. The temperature of the reactor was held at 75° C. for1 hour with stirring; then a monomer mixture comprising 7 parts ofacrylonitrile, 8 parts of methyl methacrylate and 22 parts ofα-methylstyrene was incrementally added in portions into the reactoronce every hour over a period of 5 hours through a syringe pump. At thethird hour an additional 0.3 parts of Na₂ S₂ O₈ was added into thereactor for maintaining the reaction rate. The resulting mixture wasallowed to react for 1.5 more hours more after the incrementaladditions. After completion of the reaction, the polymer was recoveredthrough freeze coagulation of the latex. The polymer was filtered, andwas then stirred with excess methanol overnight to remove residualmonomers. The polymer was filtered again and dried in a vacuum oven for24 hours at 60° C. A powdery tetrapolymer was obtain in an 88 percentyield. Its composition, as determined by gas chromatograph analysis ofredsidual monomers and the yield, was 25 acrylonitrile, 21 methylmethacrylate, 33 α-methylstyrene and 21 indene, all in weight percent.The inherent viscosity was 0.230.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with a mixing brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. Each resin plaque thus prepared wastested for HDT, melt index, tensile strength and other physicalproperties, as noted below:

The HDT of the blend was 81.5° C., the tensile strength was 8,800 psi,the flexural strength was 14,300 psi and the flexural modulus 460,000psi. The melt index of the blend was 5.1 g./10 min.

EXAMPLE H

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    25         Acrylonitrile    20         Methyl Methacrylate    10         Styrene    45         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 25 parts of Acrylonitrile, 10parts of methyl methacrylate and 45 parts of indene were charged into areactor provided with a stirrer. The reactor was purged with nitrogen,and was kept under nitrogen pressure. The temperature of the reactor washeld for 5 minutes at 65° C. with stirring; then a monomer mixturecomprising 0.4 parts of 2,2'-azobis(2,4-dimethylvaleronitrile), 10 partsof methyl methacrylate and 10 parts of styrene is added continually intothe reactor over a period of 12 hours through a syringe pump. Theresulting mixture was further allowed to react for 6 more hours. Aftercompletion of the reaction, the polymer obtained was dissolved intoacetone, and reprecipitated in excess methanol. The polymer was filteredand dried in avacuum oven for 24 hrs at 60° C. A powdery tetrapolymerwas obtained in a 43 percent yield. The composition of the polymer inweight percent was 25 acrylonitrile, 28 methyl methacrylate, 7 styreneand 40 indene as determined by C¹³ NMR. The inherent viscosity was0.152.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties, as noted below:

The HDT was 76° C., the melt index was 3.3, the tensile strength was8,800 psi, the flexural strength was 12,600 psi and the flexural modulus460,000 psi.

When a mixture was prepared having 35 weight percent of thetetrapolymer, the HDT was 79.5, the melt index was 8.0, the tensilestrength was 8,000 psi, the flexural strength was 8,600 psi, and theflexural modulus was 440,000 psi.

EXAMPLE I

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2.2'-azobis (2.4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    25         Acrylonitrile    10         Methyl Methacrylate    20         Styrene    45         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 25 parts of Acrylonitrile, 5parts of methyl methacrylate, 2 of styrene and 45 parts of indene werecharged into a reactor provided with a stirrer. The reactor was purgedwith nitrogen, and was kept under nitrogen pressure. The temperature ofthe reactor was held for 5 minutes at 65° C. with stirring; then amonomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 5 parts of methyl methacrylateand 18 parts of styrene was added continually into the reactor over aperiod of 12 hours through a syringe pump. The resulting mixture wasfurther allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered and dried ina vacuum oven for 24 hrs at 60° C. A powdery tetrapolymer was obtainedin a 50 percent yield. The composition of the polymer in weight percentwas 30 acrylonitrile, 13 methyl methacrylate, 22 styrene and 35 indeneas determined by C¹³ NMR. The inherent viscosity was 0.175.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestength and other physical properties, as noted below:

The HDT was 74.5° C., the melt index was 3.0, the tensile strength was10,000 psi, the flexural strength was 10,400 psi and the flexuralmodulus 450,000 psi.

When a mixture was prepared having 35 weight percent of thetetrapolymer, the HDT was 77.5° C., the melt index was 7.0, the tensilstrength was 8,600 psi, the flexural strength was 10,300 psi, and theflexural modulus was 480,000 psi.

EXAMPLE J

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    20         Methyl Methacrylate    20         Styrene    40         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of Acrylonitrile and 40parts of indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring. Then 20 parts of MMA was added at a constant rate with asyringe pump over a period of 8.5 hours and using another syringe pump20 parts of styrene was added at a constant rate over a period of 11hours. The resulting mixture was further allowed to react for 6 morehours. After completion of the reaction, the polymer obtained wasdissolved into acetone, and reprecipitated in excess methanol. Thepolymer was filtered and dried in a vacuum oven for 24 hrs at 60° C. Apowdery tetrapolymer was obtained in a 50 percent yield. The compositionof the polymer in weight percent was 22 acrylonitrile, 24 methylmethacrylate, 23 styrene and 31 indene as determined by C¹³ NMR. Theinherent viscosity was 0.194.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties, as noted below:

The HDT was 77° C., the melt index was 4.1, the tensile strength was9,400 psi, the flexural strength was 11,000 psi and the flexural modulus450,000 psi.

EXAMPLE K

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    10         Methyl Methacrylate    30         Styrene    40         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of Acrylonitrile and 40parts of indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring. Then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 10 parts of methyl methacrylate,and 30 parts of styrene was added continually into the reactor over aperiod of 12 hours through a syringe pump. The resulting mixture wasfurther allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered and dried ina vacuum oven for 24 hrs at 60° C. A powdery tetrapolymer was obtainedin a 51 percent yield. The composition of the polymer in weight percentwas 25 acrylonitrile, 15 methyl methacrylate, 35 styrene, and 25 indene,as determined by C¹³ NMR. The inherent viscosity was 0.184.

35 parts by weight of the tetrapolymer was mixed with 65 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties, as noted below:

The HDT was 75.5° C., the melt index was 11.2, the tensile strength was7,500 psi, the flexural strength was 8,400 psi and the flexural modulus440,000 psi.

EXAMPLE L

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    30         Methyl Methacrylate    20         Styrene    30         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of Acrylonitrile, 5parts of methyl methacrylate and 30 parts of indene were charged into areactor provided with a stirrer. The reactor was purged with nitrogen,and was kept under nitrogen pressure. The temperature of the reactor washeld for 5 minutes at 65° C. with stirring. Then a monomer mixturecomprising 0.4 parts of 2,2'-azobis(2,4-dimethylvaleronitrile), 25 partsof methyl methacrylate, and 20 parts of styrene was added continuallyinto the reactor over a period of 12 hours through a syringe pump. Theresulting mixture was further allowed to react for 6 more hours. Aftlercompletion of the reaction, the polymer obtained was dissolved intoacetone, and reprecipitated in excess methanol. The polymer was filteredand dried in a vacuum oven for 24 hrs at 60° C. A powdery tetrapolymerwas obtained in a 54 percent yield. The composition of the polymer inweight percent was 20 acrylonitrile, 29 methyl methacrylate, 14 styreneand 37 indene as determined by C¹³ NMR. The inherent viscosity was0.226.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties, as noted below:

The HDT was 78° C., the melt index was 4.3, the tensile strength was9,600 psi, the flexural strength was 11,300 psi and the flexural modulus450,000 psi.

When a mixture was prepared having 35 weight percent of thetetrapolymer, the HDT was 79.5° C., the melt index was 7.3, the tensilestrength was 9,100 psi, the flexural strength was 9,100 psi, and theflexural modulus was 460,000 psi.

EXAMPLE M

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    200        H.sub.2 O    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    30         Methyl Methacrylate    10         Styrene    40         Indene    0.6        Catalyst: 2,5-dimethyl-2,5-               bis (benzoylperoxy) hexane    ______________________________________

100 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in 100 parts of water), 0.4 parts of the catalyst, 20 parts ofAcrylonitrile, 7.5 parts of of methyl methacrylate and 40 parts ofindene were charged into a reactor provided with a stirrer. The reactorwas purged with nitrogen, and was kept under nitrogen pressure. Thetemperature of the reactor was held for 0.5 hours at 100° C. withstirring. Then a monomer mixture comprising 0.2 hours of the catalyst.22.5 parts of methyl methacrylate, and 10 parts of styrene was addedcontinually into the reactor over a period of 10 hours.

The polymer was allowed to settle and the water decanted. Thereafter thepolymer was washed with methanol, filtered and dried. Conversion was 69percent to the tetrapolymer having a composition in weight percent of 21acrylonitrile, 40 methyl methacrylate, 9 styrene and 29 indene asdetermined by C¹³ MMR. Its inherent viscosity was 0.154.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties, as noted below:

The HDT was 75.5° C., the melt index was 4.5, the tensile strength was9,700 psi, the flexural strength was 12,600 psi and the flexural modulus470,000 psi.

EXAMPLE N

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe in which amounts are shown in weight parts per 100total parts of the monomers.

    ______________________________________                           Initial                  Total Charge                           Charge  Metering                  PHM      PHM     Syringe    ______________________________________    Water           297        297    Dioctylsulfosuccinate                    2.7        2.7    (75% soln. in ethanol)    Acrylonitrile   20         12       8    Methyl Methacrylate                    30         18      12    α-methylstyrene                    20         12       8    Indene          30         18      12    Sodium persulfate (10%)                    10          4    ______________________________________

A 1-liter, 3-necked flask was fitted with a Teflon-bladed stirrer, athermometer, a reflux condenser, a septum and a nitrogen inlet at thetop of the condenser. The nitrogen line was fitted with a T and a waterbubbler to maintain a constant, slight positive nitrogen pressure in thereactor. The reactor (3-necked flask) was suspended in a glycerolheating bath maintained at a constant temperature. A syringe meteringpump was used to meter in part of the monomer during the polymerization.

The flask was charged with the water, emulsifier, and monomers andbubbled with a strong nitrogen stream to remove oxygen. The neck openingwas capped with a rubber septum and the flask was heated. The flaskcontents were maintained under a nitrogen atmosphere and stirred atabout 200 rmp. When the flask contents reached 65° C., 4 ml of a 10percent solution of sodium persulfate was injected into the reactor. Thereaction temperature remained constant at 65° C. throughout the reactiontime.

After the reaction had progressed for 1 hour, the metering pump wasturned on. The metering pump contained the quantity of monomer shown inthe recipe. The monomer was metered into the reactor during a 13 hourperiod at a constant rate.

During the polymerization, the other 10 ml of catalyst (10 percent Na₂S₂ O₈) was injected into the reactor in two equal portions; 3 ml at 4.25hours and 3 ml at 7.75 hours.

At the end of the monomer metering period, the temperature and stirringwas maintained for 8.75 additional hours. Then the polymer latex wasallowed to cool. A total solids determination on the latex indicated aconversion of 80.4 percent.

C¹³ NMR indicated a polymer composition of 21 percent acrylonitrile, 40percent methyl methacrylate, 17 percent α-methylstyrene and 22 percentindene, all in weight percent.

The cooled latex was filtered through cheesecloth, collecting 3.5 partsby weight (when dried) of a finely-divided prefloc (powder when dried).After coogulation the polymer was later collected on a filter by vacuumfiltration. The polymer particles were flushed with water then withmethanol to remove water and monomer from the particle surfaces. Thepolymer particles were then stirred in some methanol and again filtered.The powder was then allowed to stand in methanol overnight to furthersoak out monomer. After again filtering and air drying, the polymer wasdried overnight in a vacuum oven at 80° C. The product had theappearance of glistening, white sugary-type powder.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 diciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties. The results were as noted below:

The HDT was 80° C., the tensile strength was 9,800 psi, the flexuralstrength was 9,100 psi and the flexural modulus 450,000 psi.

The inherent viscosity of the tetrapolymer (0.2 percent solution in DMFat 25° C.) was 0.205.

EXAMPLE O

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe in a 10 gallon, stainless steel reactor equipped with aheating jacket, and a stirrer.

    ______________________________________                           Total   Initial                                         Monomers             PHM   PHM     Charge  Charge                                         Added             Dry   Wet     (kg)    (kg)  (kg)    ______________________________________    Water      --      191     19.1  19.1  --    Sodium Lauryl               3.0     3.0     .25   .25   --    Sulfate    Na.sub.3 PO.sub.4 12H.sub.2 O               1.0     1.0     .10   .10   --    Acrylonitrile               25      25      2.5   2.0   .5    Methyl Methacrylate               20      20      2.0   1.5   .5    α-Methyl Styrene               30      30      3.0   1.0   2.0    Indene     25      25      2.5   2.5   --    Sodium Persulfate               1.2     12      1.2   .6    --    (10%)    ______________________________________

The reactor was charged with the ingredients listed under initial chargein the recipe above, except for the persulfate catalyst. The reactor wasbuttoned down and the oxygen removed by alternately applying a vacuumand nitrogen pressure three times. The reactor was then pressure testedwith nitrogen at 50 psi.

The stirrer was set at 150 ft/min tip speed, and heat applied. At 75°C., 500 g of 10 percent solution of the persulfate catalyst was added.Total solids were taken at intervals to follow the conversion; After thefirst hour 5 incremental additions of the added monomers were made eachhour.

During the polymerization, the other 600 g of catalyst (10 percent Na₂S₂ O₈) was injected into the reactor in two equal portions; 300 g at 2.5hours and 300 g at 4.5 hours.

At the end of the monomer addition period, the temperature and stirringwas maintained for 1 additional hour. Then the polymer latex was allowedto cool.

A gas chromatographic analysis of the unreacted monomers indicated aconversion of 88 percent, a polymer composition of 25 percentacrylonitrile, 21 percent methyl methacrylate, 33 percentα-methylstyrene and 21 percent indene.

The cooled latex was filtered through cheesecloth. The cooled latex wasfreeze coagulated, filtered and the polymer collected on a filter byvacuum filtration. The polymer particles were flushed with water thenwith methanol to remove water and monomer from the particle surfaces.The polymer particles were then stirred in some methanol and againfiltered. The powder was then allowed to stand in methanol overnight tofurther soak out monomer. After again filtering and air drying, thepolymer was dried overnight in a vacuum oven at 80° C. The product hadthe appearance of glistening, white sugary-type powder.

The inherent viscosity of the tetrapolymer was 0.256.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsThermolite 813 by a blender. The mixture was kneaded for 5 minutes witha mixing brabender having a surface temperature of 190° C. into a sheet,then a plaque. Each resin plaque thus prepared was tested for HDT, meltindex, tensile strength and other physical properties, as noted below:

The HDT was 81° C., the melt index was 6.0, the tensile strength was9,300 psi, the flexural strength was 14,300 psi, and the flexuralmodulus was 460,000 psi.

EXAMPLE P

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe in which amounts are shown in parts by weight.

    ______________________________________             PHM   PHM     Total   Initial                                         Metering             Dry   Wet     Charge  Charge                                         Syringe    ______________________________________    Water      --      191     382   382   --    Sodium Lauryl               2.5     2.5     5.0    5    --    Sulfate    Na.sub.3 PO.sub.4 , 12H.sub.2 O               1.0     1.0     2.0   2     --    Acrylonitrile               25      25      50    36    14    Methyl Methacrylate               20      20      40    24    16    α-Methyl Styrene               30      30      60    16    44    Indene     25      25      50    50    --    Sodium Persulfate               1.0     10      20    10    --    (10%)    ______________________________________

A 1-liter, 3-necked flask was fitted with a Teflon-bladed stirrer, athermometer, a reflux condenser, a septum and a nitrogen inlet at thetop of the condenser. The nitrogen line was fitted with a T and a waterbubbler to maintain a constant, slight positive nitrogen pressure in thereactor. The reactor (3-necked flask) was suspended in a glycerolheating bath maintained at a constant temperature. A syringe meteringpump was used to meter in part of the monomer during the polymerization.

The flask was charged with the water, emulsifier, and monomers andbubbled with a strong nitrogen stream to remove oxygen. The neck openingwas capped with a rubber septum and the flask was heated. The flaskcontents were maintained under a nitrogen atmosphere and stirred atabout 200 rpm. When the flask contents reached 75° C., 10 ml of a 10percent solution of sodium persulfate was injected into the reactor. Thereaction temperature remained constant at 75° C. throughout the reactiontime.

After the reaction had progressed for 0.5 hour, the metering pump wasturned on. The metering pump contained the quantity of monomer shown inthe recipe. The monomer was metered into the reaction during a 5 hourperiod at a constant rate.

After 2.5 hours polymerization, 5 ml of catalyst (10 percent Na₂ S₂ O₈)was injected into the reactor, and 5 ml after 4.5 hours.

At the end of the monomer metering period, the temperature and stirringwas maintained for 1.0 additional hour. Then the polymer latex wasallowed to cool. A total solids determination on the latex indicated aconversion of 87 percent.

A gas chromatographic analysis of the unreacted monomers indicated aconversion of 89 percent, a polymer composition of 25 percentacrylonitrile, 21 percent methyl methacrylate, 33 percentα-methylstyrene and 21 percent indene.

The cooled latex was filtered through cheesecloth, collecting 3.5 partsby weight (when dried) of a finely-divided prefloc (powder when dried).The polymer latex was freeze coagulated and later collected on a filterby vacuum filtration. The polymer particles were flushed with water thenwith methanol to remove water and monomer from the particle surfaces.The polymer particles were then stirred in some methanol and againfiltered. The powder was then allowed to stand in methanol overnight tofurther soak out monomer. After again filtering and air drying, thepolymer was dried overnight in a vacuum oven at 80° C. The product hadthe appearance of glistening, white sugary-type powder. The inherentviscosity of the tetrapolymer was 0.227.

Analysis of the polymer by gas chromatography (polymer dissolved in THF)showed that it contained about 0.21 percent indene monomer and no othermonomers.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 deciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties. The results were as noted below:

The HDT was 78° C., the melt index was 3.3, the tensile strength was9,800 psi, the flexural strength was 9,300 psi and the flexural modulus395,000 psi.

EXAMPLE Q

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe in which amounts are shown in weight parts per 100total parts of the monomers.

    ______________________________________    Water              200    Triton 770.sup.(a) 0.33    Acrylonitrile      25    Methyl Methacrylate                       20    α-Methylstyrene                       30    Indene             25    Na.sub.3 PO.sub.4 .12H.sub. 2 O                       1    Sodium Persulfate  1.3    Sodium Lauryl Sulfate                       3    ______________________________________     .sup.(a) sodium alkylaryl ether sulfate 30 percent, 2propanol 23 percent     and water 47 percent

Sodium lauryl sulfate, the sodium phosphate and triton 770 weredissolved in water and charged to the reactor fitted with a coolingcondenser. The reactor contents were placed under a nitrogen atmosphere.The reactor was charged with a monomer mixture consisting of 20 phmacrylonitrile, 15 phm methyl methacrylate, 10 phm α-methylstyrene and 25phm indene. The contents of the reactor were heated to 75° C. andagitated with a mechanical stirrer.

Polymerization was initiated by adding 0.8 phm Na₂ S₂ O₈. A monomermixture consisting of 5 phm acrylonitrile, 5 phm methyl methacrylate and20 phm α-methylstyrene was introduced in measurements starting at 1 hourafter the beginning of polymerization. The exact amounts were asfollowing:

    ______________________________________            1 hour        13.3%            2 hours       13.3%            2.25 hours    13.3%            3 hours       20%            4 hours       20%            5 hours       20%    ______________________________________

In addition, 0.3 phm and 0.2 phm of additional Na₂ S₂ O₈ were added at 3hours and 5 hours, respectively.

After 7 hours the polymerization reached a monomer conversion of 87percent as determined by the solids measurements. Its inherent viscositywas 0.206. Its composition in weight percent was 23 acrylonitrile, 29methyl methacrylate, 32 α-methylstyrene and 16 indene, as measured byC¹³ NMR.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 diciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties. The results were as noted below:

The HDT was 81° C., the melt index was 3.1, the tensile strength was9,800 psi, the flexural strength was 8,200 psi and the flexural moduluswas 460,000 psi.

EXAMPLE R

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe in which amounts are shown in weight parts per 100total parts of the monomers.

    ______________________________________    Water              200    Acrylonitrile      25    Methyl Methacrylate                       20    α-Methylstyrene                       30    Indene             25    Na.sub.3 PO.sub.4 . 12H.sub.2 O                        1    Sodium Persulfate  1.0    Sodium Lauryl Sulfate                        3    ______________________________________

Sodium lauryl sulfate and the sodium phosphate were dissolved in waterand charged to the reactor fitted with a cooling condenser. The reactorcontents were placed under a nitrogen atmosphere. The reactor wascharged with a monomer mixture consisting of 20 phm acrylonitrile, 15phm methyl methacrylate, 10 phm α-methylstyrene and 25 phm indene. Thecontents of the reactor were heated to 75° C. and agitated with amechanical stirrer.

Polymerization was initiated by adding 0.7 phm Na₂ S₂ O₈. A monomermixture consisting of 5 phm acrylonitrile, 5 phm methyl methacrylate and20 phm α-methylstyrene was introduced in measurements starting at 1 hourafter the beginning of polymerization. The exact amounts were asfollowing:

    ______________________________________            1 hour                  20%            2 hours                  20%            3 hours                  20%            4 hours                  20%            5 hours                  20%    ______________________________________

In addition, 0.3 phm and 0.2 phm of additional Na₂ S₂ O₈ was added at 3hours and 5 hrs, respectively.

After 6 hours the polymerization reached a monomer conversion of 88.7percent as determined by the solids measurements. Its inherent viscositywas 0.228. Its composition in weight percent was 25 acrylonitrile, 21methyl methacrylate, 35 α-methylstyrene and 20 indene, as measured bygas chromatography analysis of the residual monomers.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 diciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties. The results were as noted below:

The HDT was 77.5° C., the melt index was 3.9, the tensile strength was9,500 psi, the flexural strength was 12,440 psi and the flexural moduluswas 470,000 psi.

EXAMPLE S

A tetrapolymer was made by emulsion polymerization according to thefollowing recipe in which amounts are shown in weight parts per 100total parts of the monomers.

    ______________________________________                    PHM    ______________________________________    Water             200    Acrylonitrile     25    Methyl Methacrylate                      20    α-Methylstyrene                      30    Indene            25    Na.sub.3 PO.sub.4 . 12H.sub.2 O                       1    Sodium Persulfate 1.0    Sodium Lauryl Sulfate                       3    ______________________________________

Sodium lauryl sulfate and the sodium phosphate were dissolved in waterand charged to the reactor fitted with a cooling condenser. The reactorcontents were placed under a nitrogen atmosphere. The reactor wascharged with a monomer mixture consisting of 17 phm acrylonitrile, 11phm methyl methacrylate, 10 phm α-methylstyrene and 25 phm indene. Thecontents of the reactor were heated to 75° C. and agitated with amechanical stirrer.

Polymerization was initiated by adding 0.7 phm Na₂ S₂ O₈. A monomermixture consisting of 8 phm acrylonitrile, 9 phm methyl methacrylate and20 phm α-methylstyrene was introduced in measurements starting at 1 hourafter the beginning of polymerization. The exact amounts were asfollowing:

    ______________________________________            1 hour                  20%            2 hours                  20%            3 hours                  20%            4 hours                  20%            5 hours                  20%    ______________________________________

In addition, 0.3 phm and 0.2 phm of additional Na₂ S₂ O₈ was added at 3hours and 5 hours, respectively.

After 7 hours the polymerization reached a monomer conversion of 88percent as determined by the solids measurements. Its inherent viscositywas 0.224. Its composition in weight percent was 25 acrylonitrile, 21methyl methacrylate, 36 α-methylstyrene and 18 indene, as measured bygas chromatography analysis of the residual monomers.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofinjection grade PVC (inherent viscosity 0.68 diciliters/gm) and 3 partsof Thermolite 813 by a blender. The mixture was kneaded for 5 minuteswith a mixing brabender having a surface temperature of 190° C. Theresulting blend was press formed at 190° C. into a sheet, then a plaque.Each resin plaque thus prepared was tested for HDT, melt index, tensilestrength and other physical properties as noted below:

The HDT was 79.5° C., the melt index was 2.9, the tensile strength was9,900 psi, the flexural strength was 14,300 psi and the flexural moduluswas 430,000 psi.

In the following example the poly(vinyl chloride) used was a commercialextrusion grade PVC having an inherent viscosity of 0.93 deciliters/gramfor a 0.2 weight percent solution in cyclohexanone measured at 25° C.When compounded with 3 parts of Thermolite 813 per 100 weight parts ofPVC, the stabilized PVC had an HDT of 72° C., a tensile strength of10,000 psi, a flexural strength of 13,700 psi and a flexural modulus of460,000 psi. Its melt index was not measurable.

EXAMPLE T

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    20         Methyl Methacrylate    20         α-Methylstyrene    40         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of Acrylonitrile, 10parts of methyl methacrylate, 10 parts of α-methylstyrene, and 40 partsof indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 10 parts of methyl methacrylateand 10 parts of α-methylstyrene was added continually into the reactorover a period of 10 hours through a syringe pump. The resulting mixturewas further allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered, and driedin a vacuum oven for 24 hours at 60° C. A powdery tetrapolymer wasobtained. The composition of the polymer was 23 acrylonitrile, 20 methylmethacrylate, 34 α-methylstyrene and 22 indene as determined by C¹³ NMR.The inherent viscosity was 0.172.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofextrusion grade PVC and 3 parts of Thermolite 813 by a blender. Themixture was kneaded for 5 minutes with mixing a brabender having asurface temperature of 190° C. The resulting blend was press formed at190° C. into a sheet, then a plaque. A resin plaque thus prepared wastested for HDT, which was 80° C., melt index, tensile strength and otherphysical properties.

The HDT was 80° C., the melt index was 0.12/10 min, the tensile strengthwas 11,300 psi, the flexural strength was 16,300 psi and the flexuralmodulus 510,000 psi.

In the following example the poly(vinyl chloride) used was a commercialextrusion grade PVC having an inherent viscosity of 0.93, and whencompounded with 3 weight parts the diisooctyl ester of dibutyltindimercaptoacetic acid, (C₈ H₁₇ SCH₂ COO)₂ Sn(C₄ H₉)₂, thermal stabilizerand 1 part of oxidized ethylene homopolymer lubricant per 100 parts ofPVC, the stabilized PVC had an HDT of 67° C., a tensile strength of9,400 psi, a flexural strength of 13,200 psi, and a flexural modulus of430,000 psi. Its melt index was not measurable.

EXAMPLE U

A tetrapolymer was made by suspension polymerization according to thefollowing recipe. Amounts are in weight parts per 100 parts of totalmonomers.

    ______________________________________    PHM        Components    ______________________________________    150        H.sub.2 O    0.6        2,2'-azobis (2,4-dimethylvaleronitrile)    0.2        Hydroxylethylcellose (suspending agent)    20         Acrylonitrile    30         Methyl Methacrylate    10         Styrene    40         Indene    ______________________________________

150 parts by weight of distilled water, 0.2 parts of HEC (which has beendissolved in water), 0.2 parts of2,2'-azobis(2,4-dimethylvaleronitrile), 20 parts of Acrylonitrile, 15parts of methyl methacrylate, 2 parts of α-methylstyrene, and 40 partsof indene were charged into a reactor provided with a stirrer. Thereactor was purged with nitrogen, and was kept under nitrogen pressure.The temperature of the reactor was held for 5 minutes at 65° C. withstirring; then a monomer mixture comprising 0.4 parts of2,2'-azobis(2,4-dimethylvaleronitrile). 15 parts of methyl methacrylateand 8 parts of α-methylstyrene was added continually into the reactorover a period of 8 hours through a syringe pump. The resulting mixturewas further allowed to react for 6 more hours. After completion of thereaction, the polymer obtained was dissolved into acetone, andreprecipitated in excess methanol. The polymer was filtered, and driedin a vacuum oven for 24 hours at 60° C. A powdery tetrapolymer wasobtained. The composition of the polymer was 19 acrylonitrile, 41 methylmethacrylate, 16 styrene and 23 indene as determined by C¹³ NMR. Theinherent viscosity was 0.215.

25 parts by weight of the tetrapolymer was mixed with 75 parts ofextrusion grade PVC and 3 parts of the diisooctyl ester of di-n-butyltindimercaptoacetic acid as thermostabilizer and 1 part of oxidizedethylene homopolymer as lubricant by a blender. The mixture was kneadedfor 5 minutes with a mixing brabender having a surface temperature of190° C. The resulting blend was press formed at 190° C. into a sheet,then a plaque. Each resin plaque thus prepared was tested for HDT, meltindex, tensile strength and other physical properties.

The HDT was 74.5° C., the melt index was 0.64/10 min, the tensilestrength was 9,700 psi, the flexural strength was 12,100 psi and theflexural modulus 470,000 psi.

As will be evident to those skilled in the art, various modifications ofthis invention can be made or followed in the light of the foregoingdisclosure and discussion without departing from the spirit and scope ofthe disclosure or from the scope of the claims.

We claim:
 1. A composition comprising an intimate admixture of(a) 50 to98 parts by weight of a vinyl chloride polymer having an inherentviscosity of at least 0.4 and (b) 50 to 2 parts by weight of a randomaddition tetrapolymer containing the following monomers combined in thepolymer structure in the following weight percentages:

    ______________________________________                   Weight Percent    ______________________________________    Acrylonitrile    15-35    Methyl methacrylate                     5-45    Indene           5-45    α-methylstyrene or                     5-45    styrene or a    mixture of both    ______________________________________

where (a) plus (b) total 100 parts by weight, and the total parts byweight of combined indene plus α-methyl styrene plus styrene in thetetrapolymer (b) is 38-70 parts by weight.
 2. A composition comprisingan intimate admixture of(a) 50 to 98 parts by weight of a vinyl chloridepolymer having an inherent viscosity of at least 0.4 and (b) 50 to 2parts by weight of a random addition tetrapolymer containing thefollowing monomers combined in the polymer structure in the followingweight percentages:

    ______________________________________                   Weight Percent    ______________________________________    Acrylonitrile    20-30    Methyl methacrylate                     15-30    Indene           10-30    α-methylstyrene or                     15-40    styrene or a    mixture of both    ______________________________________

where (a) plus (b) total 100 parts by weight, and the total parts byweight of combined indene plus α-methyl styrene plus styrene in thetetrapolymer (b) is 45-60 parts by weight.